diff --git a/zuul_sphinx/zuul.py b/zuul_sphinx/zuul.py
index f578884..bb669be 100644
--- a/zuul_sphinx/zuul.py
+++ b/zuul_sphinx/zuul.py
@@ -79,7 +79,7 @@ class ZuulDirective(Directive):
 
     def find_zuul_yaml(self):
         root = self.state.document.settings.env.relfn2path('.')[1]
-        while root:
+        while root and root != '/':
             for fn in ['zuul.yaml', '.zuul.yaml', 'zuul.d', '.zuul.d']:
                 path = os.path.join(root, fn)
                 if os.path.exists(path):